1. Technical Field
This invention relates to acoustics, and more particularly, to a system that enhances the perceptual quality of a processed voice.
2. Related Art
Many hands-free communication devices acquire, assimilate, and transfer a voice signal. Voice signals pass from one system to another through a communication medium. In some systems, including some used in vehicles, the clarity of the voice signal does not depend on the quality of the communication system or the quality of the communication medium. When noise occurs near a source or a receiver, distortion garbles the voice signal, destroys information, and in some instances, masks the voice signal so that it is not recognized by a listener.
Noise, which may be annoying, distracting, or results in a loss of information, may come from many sources. Within a vehicle, noise may be created by the engine, the road, the tires, or by the movement of air. A natural or artificial movement of air may be heard across a broad frequency range. Continuous fluctuations in amplitude and frequency may make wind noise difficult to overcome and degrade the intelligibility of a voice signal.
Many systems attempt to counteract the effects of wind noise. Some systems rely on a variety of sound-suppressing and dampening materials throughout an interior to ensure a quiet and comfortable environment. Other systems attempt to average out varying wind-induced pressures that press against a receiver. These noise reducers may take many shapes to filter out selected pressures making them difficult to design to the many interiors of a vehicle. Another problem with some speech enhancement systems is that of detecting wind noise in a background of a continuous noise. Yet another problem with some speech enhancement systems is that they do not easily adapt to other communication systems that are susceptible to wind noise.
Therefore there is a need for a system that counteracts wind noise across a varying frequency range.